THEORIES OF DEVELOPMENT 



of acquired characters, Mr. Burbank answers em- 

 phatically in the affirmative. As he sees the mat- 

 ter, all traits of every species were at some time 

 acquired in response to environmental stimuli. 

 To deny the transmissibility of new traits thus 

 acquired from time to time in the geological ages 

 would be tantamount to denying evolution itself. 

 He finds that plants of closely related species 

 brought from different continents transmit their 

 qualities when interbred; and he has little pa- 

 tience with the modern quibble which would admit 

 the transmissibility of qualities imprinted directly 

 on the germ-plasm, while denying transmissibility 

 of the changes in the body-plasm, in view of the 

 fact that the germ-plasm itself is part of the plant 

 body and, moreover, is apparently disseminated 

 everywhere throughout the plant organism, inas- 

 much as individual buds or pieces of stalk, or bits 

 of root or bulb, may in numberless instances re- 

 produce the entire plant quite as effectively as it 

 is reproduced from the seed. 



In thus advocating the theory of the universal- 

 ity of acquired traits, however, Mr. Burbank of 

 course does not refer to gross lesions ; and it may 

 be added that he has not personally conducted any 

 experiments in the attempted modification of the 

 germ-plasm through use of chemicals or of radium 

 such as some other workers are now undertaking. 



[27] 



